Transcript Psych B – Module 22

Chapter 9:
States of Consciousness
Module 22:
Drugs
Psychoactive Drug
• A chemical substance
that alters perceptions,
mood, or behavior
• Three common
psychoactive drugs:
– Caffeine
– Alcohol
– Nicotine
• Induce an altered state
of consciousness
Dependence
• A state of
physiological and/or
psychological need
to take more of a
substance after
continued use.
– Withdrawal follows
if the drug is
discontinued
Withdrawal
Tolerance
• The discomfort and
• Reduced
distress that follow
responsiveness to a
when a person who
drug, prompting the
is dependent on a
user to increase the
drug discontinues the
dosage to achieve
use of the drug
effects previously
obtained by lower
– Withdrawal
symptoms are usually
doses of the drug
the reverse of the
drug’s effects.
Tolerance
Module 22: Drugs
Drugs and
Neurotransmission
Neurotransmission
• The process whereby neurons
communicate with each other
– Neurotransmission, especially in the brain
and spinal cord, helps explain the effects of
psychoactive drugs.
• Psychoactive drugs interfere with
normal neurotransmission.
Neurotransmitters
• Chemical messengers that cross synaptic
gaps between neurons
– When released by the sending neuron,
neurotransmitters travel across the synapse
and bind to receptor sites on the receiving
neuron, setting up the next link in the chain
of communication.
Synapse
• The junction between the tip of the
sending neuron and the receptor sites on
the receiving neuron
• Call the synaptic gap or cleft
Neural
Activity
Neurotransmitters
and the Synapse
Reuptake
• Process where the
unused
neurotransmitter
chemical is
reabsorbed by the
sending neuron
– How anti-depressants
work; they facilitate
the reuptake
Module 22: Drugs
Drug Classifications
Psychoactive Drugs and Synapses
• Psychoactive drugs affect synapses and
neurotransmitters in three ways:
– Binding with receptors
– Blocking receptor site
– Blocking neurotransmitters’ reuptake
Five Psychoactive Drug Categories
• Five different categories we will study:
– #1. Depressants
– #2. Opiates
– #3. Stimulants
– #4. Hallucinogens
– #5. Marijuana
Module 22: Drugs
Drug Classifications:
#1. Depressants
#1. Depressants
• Drugs that reduce neural activity and
slow body functioning
– Includes alcohol and sedatives
Depressants: Alcohol (ethyl alcohol)
• Found in beer, wine,
and liquor
• The second most
used psychoactive
drug (caffeine first)
• Slows thinking, and
impairs physical
activity
• A measure of how
much alcohol is in a
person’s bloodstream
• BAC of .08
considered legal
intoxication in most
states
Affects of Alcohol
Euphoric
Memory & Sleep
• Alcohol impairs the
parts of the brain
responsible for
controlling
inhibitions and
making judgments
• Studies have shown
that alcohol impairs
memory by
suppressing the
processing of events
into long term
memory.
• Alcohol impairs
REM sleep, further
disrupting memory
storage.
Do you have an alcohol problem?
Depressants: Sedatives
• Drugs that reduce anxiety or induce
sleep
– Also called tranquilizers
• Include barbiturates and
benzodiazepines
Barbiturates
• Drugs that depress the
activity of the central
nervous system and
thereby reduce anxiety
– Can be lethal in
overdose and interact
with other drugs,
especially alcohol
• Impair both memory
and judgment
• Can create tolerance
and dependence
Benzodiazepines
• Drugs that depress
that activity of the
central nervous
system without most
of the side effects
associated with
barbiturates
• Include Valium and
Xanax
• Can create
dependency
Module 22: Drugs
Drug Classifications:
#2. Opiates
#2. Opiates
• Drugs that depress neural activity,
temporarily lesson pain and anxiety
• Include: opium, morphine, and heroin
Opiates: Morphine
• Strong sedative and
pain-relieving drug
derived from opium
• Works by preventing
pain neurons from
firing or releasing
pain-signaling
neurotransmitters
into the synapse
&
Endorphins
• Natural, opiate-like
neurotransmitters
linked to pain control
and to pleasure
• Body’s natural pain
killers
Module 22: Drugs
Drug Classifications:
#3. Stimulants
#3. Stimulants
• Drugs that excite neural activity and
speed up body functions
• Include: caffeine, nicotine,
amphetamines, and cocaine
Caffeine
• Stimulant found in
coffee, chocolate, tea,
and some soft drinks
• Provides user with a
sense of increased
energy, mental
alertness, and forced
wakefulness
• Blocks neurological
receptor sites that , if
activated, sedate the
central nervous system
Nicotine
• Stimulant found in
tobacco
• Effects similar to
those of caffeine
• Very addictive and
does not stay in the
body very long
– Explains constant
cravings
Cocaine
• Stimulant derived
from leaves of the
coca plant
– Crack – cocaine
crystals
• Blocks the reuptake of
certain
neurotransmitters
• Dependency is quick
and severe; places
extreme strain on
cardiovascular system
Amphetamines
• Drugs that stimulate
neural activity, speeding
up body functions, with
associated energy and
mood changes
• Includes: speed, uppers,
and methamphetamines
• Mimic adrenaline
• Can cause irreversible
changes in mood
Module 22: Drugs
Drug Classifications:
#4. Hallucinogens
#4. Hallucinogens
• Drugs that distort perceptions and evoke
sensory images in the absence of
sensory input
• Include: LSD and ecstasy
• Sometimes called “psychedelics”
Lysergic Acid
Diethylamide (LSD)
• Powerful hallucinogenic
drug
• Also known as “acid”
• The effects vary from
person to person
• Users can be dangerous
to themselves and
others.
Ecstacy
• Hallucinogenic drug
that produces lower
inhibitions, pleasant
feelings, and greater
acceptance of others
• Also called MDMA
• Even moderate users
may experience
permanent brain
damage.
Module 22: Drugs
Drug Classifications:
#5: Marijuana
#5. Marijuana
• Leaves, stems, resin, and flowers form
the hemp plant that, when smoked,
lower inhibitions and produce feelings
of relaxation and mild euphoria
• THC (delta-9-tetrahydrocannabinol) is
the active ingredient
• Disrupts memory; lung damage from
smoke
Module 22: Drugs
Prevention
High School Drug Use
(Johnston & others, 2002)